Flotation apparatus



March 1931-. w. A. BUTCHART 1,798,452

FLOTATION APPARATUS Filed April 25, 1927 l INVENTOR.

BY f9 g) 4 ATTORNEY.

Patented Mar. 31, 1931 UNITED STATES WILLIAM A. BUTCHART, F .TOPLIN, MISSOURI FLO'IATION APPARATUS Application filed April 23,

This invention relates to machines for extracting Values from ores by the flotation process.

It is customary in the operation of ma chines of this type to promote and facilitate the separation of the minerals and the. forma tion of a froth in which they are carried to a point of overflow, by aeration and agitation of the ore pulp intermixed with a suitto able frothing agent, either separately or in cooperative association and the main objects of the present invention are: first, to

provide an aerating element so constructed and disposed as to prevent of its porous surface through which the air issues, from being obstructed and blinded or blanketed by settling solids; second, to promote the aeration and agitation of the material for the purpose of effecting a clean separation of the minerals and producing a froth suitable for carrying the minerals to the overflow level and having the uniform degree of den sity and volume for the subsequent recovery of the values, by introducing the air into the material in a downwardly directed current, and; third, to arrange one or more aerating elements of the above stated character in a novel cooperative relation to a mechanical agitator.

Other objects of the invention reside in details of construction as will be more fully described in the following description.

In the accompanying drawings in the sevoral views of which like parts have been similarly designated,

Figure 1 represents a sectional elevation of a flotation machine in which the present invention is embodied,

Figure 2, an enlarged transverse section taken on the line 22, Figure 1, and

Figure 3, an enlarged sectional detail of one of the air chambers included in the aerating element.

A tank or spitzkasten 5 of substantially rectangular form has at the upper edges of its sides 6 openings for the overflow of froth across slanting aprons 7 The material is fed into the tank through a conduit 8 and the gangue or tailings are discharged through an opening 9 in the bottom 1927. Serial No. 186,059.

of the vessel which communicates with a tailings box 10. The box is partially divided by a vertical weir 12 to determine the level of material in the vessel and a gate 13 sliding upon the weir provides an adjustable means to vary the elevation of the liquid level with relation to the overflow openings.

The mechanical agitator comprises a rotary paddle drum preferably disposed lengthwise in the vertical axis of the vessel adjacent the bottom of the same. The drum consists of a number of paddles 14 set in peripheral notches of disk-shaped spiders 15 which are fixed on a shaft 16. The shaft is mounted for rotation in bearings on the end Walls of the tank and the bearings are sealed against leakage of liquid from the tank by stufling boxes 17. f

A pulley 18 at an end of the shaft provides for its connection with a conveniently located motor.

The aerating element of the invention includes in the form shown in the drawing, three air chambers arranged in adjacency to the mechanical agitator centrally above and F' at opposite sides thereof. Each air chamber consists of a flat top 19 extending lengthwise of the tank, a longitudinal rib 20 on the underside of the top, and a covering 21 of canvas or other porous material fastened to J the edges of the top and the rib.

The chambers 22 thus produced, are closed at their ends and the members are fastened in place by angle brackets 23 secured to an end Wall of the tank.

Air under pressure is admitted to the air chambers through pipes 24 connected with openings 25 in thetops of the chambers and branching from a header 26 which connects with a conveniently located source of air 9% under pressure.

In the operation of the machine the pulverized o're with water and a suitable flotation agent intermixed into a pulp, are fed into the tank through the conduit 8. The pulp fills the vessel tothe level determined by the sliding gate in the weir box and power is applied toth'e pulleybausing the agitator to rotate at a suitable velocity.

Air under pressure is admitted to the air chambers 22 through the pipes 24 and 26 and this air is forced through the porous under sides 21 of the chambers into the material. The air cooperates with the movement of the agitator to separate the minerals from their gangue and produces a froth which carries the values-to thelevel of the liquid in the tank.

The mineral-bearing froth :is discharged across the overflows at the sides of the tank and subjected to further treatment for the recovery of its values.

The supply of air to the aerating element may be regulated by one or more valves in the header, not shown in the drawings.

It will be evident that the downwardly directed air-streamshave a forceful separativesaud agitative effect upon thematerial, separate from the action of the mechanical agent and that by their subsequentreversal of direction in ascending to the-:level ofthe material the air is thoroughly disseminated through thepulp .and produces a froth of the desired volume and consistency ,in which the values contained in the material are entrapped.

lVhile cooperation of the aerating and mechanical agitating elements is highly desirous to produce the desired results, it is to be understoodthat the operation is not entirely dependent upon the presence of a mechanical agitator and that the aerating element by itself may be employed with good effect.

It is obvious that settling solids cannotpossibly obstruct and blind and blanket the downwardly facing porous sides of the air chambers through which the aiiwenters the material in the tank.

Variations in the construction and arrangement of the elements may. be resorted to without departing fromthe spirit of the invention.

Having thus described my invention. what I claim and desire to secure by Letters Patent is 1. In flotation apparatus, a tank, and an element having an air chamber comprising a closed top, a :rib at the underside thereof. and a porous covering engaging the rib and fastened to the top at opposite sides of the rib.

2. In a flotation tank, an'aerating member disposed to emit air in a downwardly current, an agitator below said member, and other aerating members disposed to emit air in downwardlydirected currents at either side of the agitator.

3. In a flotationtank, .an aerating member disposed to emit air in a downwardly directed current, an agitator below said member, and other. aerating members disposed to emit air in downwardly directed currents at either side ofthe agitator, the last-mentioned aeratin members'being closerto the-bottom of the tank than the first-mentioned member.

4. In a fiotationtank, stationary aerating members extending lengthwise of the tanh and disposed to emit air in downwardly directed currents and an agitator extending lengthwise of the tank, and disposed in said currents and in adjacency to the aerating members.

5. Ina flotation tank, stationary. aerating members extending lengthwise of the tank and disposed to emit air in downwardly directed currents, and an agitator extending lengthwise o-f-the tank, and disposed below and in adjacency to the aerating members, the aerating members and the agitator being substantially the length of the tank.

6. i In a flotation tank, an aerating member comprising a closedtop, a rib-at the underside thereof,,spaced from the edges of the top, and a porous covering engaging the rib and fas tended to the top at opposite'sidcs of the rib. whereby to provide an aerating space at either side of the rib.

7. In a flotation tank, an agitator in the tank having a substantially horizontal axis. there being a Zone in the tank outside of the path of the agitator, and stationary means for issuing air into said zone.

In testimony whereof I have affixed my signature.

WILLIAM A. BUTCHART. 

